Halogenated ethers



Patented July 4, 1944 HALOGENATED ETHERS Walter J. Toussaint, SouthCharleston, W. Va., and Louis G. MacDowell, In, Lakeland, Fla assignorsto Carbide and Carbon Chemicals Corporation, a corporation of New YorkNo Drawin -s Application March '2, 1942. erial No. 477,764

7 Claims. (Cl. 260-615) This invention provides a simple and effectivemethod for making halogenated ethers. It appears to involve a novelchemical mechanism by which halogens and olefins react with certainethers by splitting the carbon-to-oxy gen-tocarbon linkage, all as morefully hereinafter set forth. The invention will be discussed withrespect to this assumed new mode of chemical action, which seems to bethe most acceptable explanation of the results obtainable, but it mustbe understood that it is merely by way of explanation, and that theinvention is not limited by any theoretical considerations advanced.

The halogenated ethers have attained an important place in industry.They have wide uses as solvents, reaction media, intermediates for thepreparation of other products and for various other purposes. One of themost common of these ethers is bis-beta-chlorethyl ether,

This compound corresponds to diethylene glycol in which the two hydroxylgroups have been replaced by chlorine atoms. Accordingly, this dichlorether, its homologues and analogues, may also be styled glycol dihalidesfor convenience. Thus, beta-chlorethyl, beta' chlor-ethoxyethyl ether,ClCHzCH2.0.CH2CI-I2.0.CH2CH2C1, may be called triethylene glycoldichloride, and related compounds can be similarly named.

The formation of the dichlordialkyl ethers by reacting olefines,chlorine and oleflne chlorhydrins in a process wherein the chlorhydrinis supplied as such or is formed by the initial reaction of water withpart of the chlorine and the olefine, has been described, for example,in Perkins Reissue Patent No. 22,217. It has also been shown in CoxPatent No. 2,017,811 that the operation of this process using ethyleneas the olefine results in the formation of some of the diether,triethylene glycol dichloride. The Cox patent does not state the yieldof triethylene glycol dichloride obtained, and as a practical matter ithas been found to be small in comparison with the main product,diethylene glycol dichloride. The present method likewise uses chlorine(or another halogen) and an olefine as starting materials, and these arecaused to react on a polyether containing two or morecarbon-to-oxygen-tocarbon linkages. The polyethers useful in the methodof this invention can be defined as those aliphatic polyethers in whichat least two alkylene groups, CnHZn, or substituted alkylene groups, arepresent, wherein the value of n in any such group does not exceed 8, andin which each of two vicinal carbon atoms of at least two of thealkylene or substituted alkylene groups is connectedv with an oxygenatom. 'Ihisaplfllcatmn is concerned with reactions involving open chainpolyether compounds, such as polyalkylene glycols (polyethers in whichthe terminal alkylene radicals possess a hydroxyl .group); polyalkylenehalohydrins (polyethersin whichone terminal alkylene radical bearaa-,hydroxyl group and the other a halogen atom): polyalkvlene glycoldichlorides (poiyethersiu which the terminal alkylene radicals ,eachbear a halogen atom); and polyalkylene'glycol monoor dialkyl or arylethers (polyethers in which the terminal alkylene groups areconnectedthrough oxygen to other radicals). Embodiments of. theinvention in which cyclic polyether compounds are involved are thesubjectot our copending application Serial No. 308,820,,filed December12, 1939.

From the known reaction or glycol chlorhydrin with oleflne and chlorineto form diglycol dichlohomologues would ofler a direct method of makingany desired polyglycol dichlorides. But as a practical matter this hasbeen found not to be the case. The reason for this is not that thedesired reactions fail to occur as taught by the prior in vestigatorsmentioned, but rather that the desired starting materials cannot besecured by any convenient means that does not result in much greateramounts of undesired (for the Cox or Perkins'reactions) products. Thus,if ethylene chlorhydrin is reacted with the theoretical amount ofethylene oxide in the absence of ethylene andj'chlorine in an eflort tomake triethylene glycol'chlorhydrin as a starting point in thepreparation of tetraethylene glycol dichloride by a reaction analogousto the Cox reaction, the product obtained contains a mixture of varioushomologous chlorhydrins and may contain also polyethylene glycols. Thesematerials must be separated from. the desired triethylene glycolchlorhydrin by separate purification steps, and because the undesiredproducts constitute the high proportion ofthe materials, the overallresult is an impractically low efliciency of operation. Alternativelydiglycol chlorhydrin can be made at higher efllciencies using relativelylow conversion, and from this, after purification, triglycol chlorhydrincan be made, again using relaproduction of valuable halogenatedethersfrom by-products and residues which result in the preparation of variousglycols, glycol ethers and chlorhydrins in the manufacture of variousindustrial products.

The unsaturated hydrocarbons and oleiines gen- .erally are useful in themethod'oithis invention, including, specifically, ethylene and varioussubstituted ethylenes, such as propylene, butylenes, amylenes andhexylenes. Of these, the oleflnes of unbranched chain structure, or'those in which theside chains, if present, are short with refer ence tothe unbranched portion, or those in which the branching occurs at apoint relatively remote from the oleflne linkage, are preferred. Thepreferred olefines, for convenience, may be termed normal oleflnes. Infact, some substituted ethylenes, including styrene (phenyle'thylene),.vinyl chloride (monochlorethylene) and; isobutylene(unsymmetrical dimethyl, ethylene), seem to enter into the reaction ofthe new method with difliculty and to only a minor extent.

The general reaction of this invention may be illustrated as follows,the particular reactants illustrated having been chosen merely. for con-Additionally, the reactions 200% over the original liquid volumepresent. This value is more or less arbitrary and represents aconvenient extent of reaction rather than a critical one. Both lower andgreater percentage volume increases have been used with good results,and in many cases higher volume increases seem desirable. The reactionhasbeen conducted at temperatures ranging from 20 C. to 650 C.'withoutnoticeably affecting the yield. So far as has been determined, the onlytemperature limitations are the freezing and boiling points of thereaction mixture. If the reaction is applied to such high molecularweight products as the solid polyethylene glycols, either a solvent forthe solid materials, for instance dioxane, ethylene dichloride or thelike, or temperatures above their melting points are required. It hasbeen found desirable at all times to maintain an excess of the oleflneand a low concentration of free halogen to reduce the occurrence ofsubstitution reactions, and to avoid the presence of explosive gaseousmixtures.

At the end of the reaction step, the products can be isolated from thereaction mixture by distillation. The actual distillation, ii desired,may

be preceded by the addition of a strong base to the reaction mixture toneutralize and decompose, respectively, any hydrogen halide and halogensubstitution products formed by side reactions. For this purpose,aqueous sodium hydroxide. a

lime suspension or any other convenient base can- Example 1 venience: I40 Ethylene and chlorine were passed into a mix- 1olcnicnroomom-o(onionrohcmomon cup-0H, Ch

Polyglycol chlorhydrin Ethylene Chlorine In the above equation n isequal to or greater than zero, and splitting can occur at any of theether oxygen atoms according to our invention.

One possible explanation of the mechanism by which the products areformed is as follows:

Triglycol dichloride ture of polyethylene glycols (polyoxyethylenediols) of an average molecular weight of about 1545 as determined byacetylation. The boiling points of the polyethylene glycol constituentsof the mixture were not lower than 240 C. at an Polyglycol chlorhydrin(2) CH2=CHI Ch CHg-CH C1- Ethylene Chlorine Ethylene N tive monochlcrideoride positiveion ion (3) CICHICHQ'OCHICHQ'O(CHICHI'O).CHQCHIOH CHr-CHgClCH CHrO-CHaCHrO(CHgCHrO)-CH:CH;OH

O HiC'HiCl Polyglyccl chlcrhydrln Positive chlorethyl ployglycolchlorhydrln ion (4) ClOHaCHrO-CH|CHrO(CHaCHI-O)-CHIGH|OH Cl- ---0HiCHaOl ClCHaCEr-O-CHaCHa-O-CHiCHiCl Cl(CHaCHr0) CH|CK|OH Triglycoldichloride Polyglycol chlorhydrin The reaction illustrated can beconducted very 7o absolute pressure of two millimeters oi mercury.

simply by diflusing chlorine and ethylene into a liquid body containingthe polyether compound. Experience has shown that good yields andemciencies are obtained when reaction has progressed After about 10hours the volume of the reaction mixture had increased by about 200percent. The addition of ethylene and chlorine was then stopped and thereaction product separated into to an extent such as to cause anincrease or about its various constituents.

Diethylene glycol dichloride c1c2moc=mc1 triethylene glycol dichloride.I

Example 2 A liquid mixture containing 915 grams of polyethylene glycolchlorhydrins, 69 grams of 1,4 dioxane and 16 grams of ethylenechlorhydrin was placed in a vertical glass cylinder 30 inches tall and 3inches in diameter. A glass coil for the circulation of cooling. waterwas immersed in the liquid, and two ceramic diffusers for the admissionof gases were located in the lower part of the cylinder.

The mixture of polyethyleneglycol chlorhydrins had an average molecularweight of 470, and contained members of the series of polyetlwleneglycol chlorhydrins of which the principal ones present were hepta-,octa-, nona-. decaand undecaethylene glycol chlorhydrins together withsmall amounts of lower polyethylene glycol chlorhydrins.

Gaseous chlorine and an excess'of ethylene were passed into this liquidmixture by means of the diffusers for a period of 15 hours. Thetemperature of the reaction mixture was .maintained at 25 to 35 C.during this period. When the gas flows were stopped, the volume of theliquid mixture had increased by 200% of the original. The crude productweighed 3245 gramsand contained 1.5% acid as hydrochloric acid. It wasneutralized by the addition of 65 grams of sodium hydroxide dissolved in200 grams of water. The neutralized product separated intov two liquidlayers, and the oil layer was separated and fractionally distilled.

Three of the desired dichloro ethers were isolated from the products,viz. 5'72 grams of bisbeta-chloroethyl ether (diethylene glycoldichloride), 558 grams of beta-chloroethyl, beta'-chloroethoxyethylether (triethylene glycol dichloride), and 269 grams of bis-beta-(beta-chloroethoxy) diethyl ether (tetraethylene glycol dichloride).There were also isolated 1400 grams of ethylene dichloride and 154 gramsof higher boiling products (probably higher polyglycol dichlorides),while 102 grams of the crude reaction mixture was accounted for asdistillation residues and 51 grams as water-soluble material.

It will be seen from these data that the extent of ether linkagesplitting accomplished by this operation of the process wasconsiderable. The starting materials were composed of less than 3 grammoles of oxygen-containing substances (polyethylene glycol chlorhydrins,dloxane and ethylene chlorhydrin) whereas the products included morethan 8 gram moles of oxygen-containing substances exclusive of thehigher boiling materials that were not specifically identified.

Other and larger scale operations gave comparable results, and newmethod has been proved excellently adapted to simple and eflicientcommercial practice.

Experiments similar to the foregoing have been conducted in whichchlorine and styrene, chlorine and isobutylene, and chlorine and vinylchloride were reacted with 1,4 dioxane. In every case, chlorine additionto the olefine occurred, and, in the case of vinyl chloride, somenaphthodioxane,

3 C CH;

was formed. In no case, however, were sufllcient amounts of. the desiredtriethylene glycol dichloride derivatives secured to permit isolationand complete identification of these.

Chlorine and ethylene react in the manner shown with glycol ethers otherthan those specifically described, for example, with the variouspolyethylene and polypropylene glycols, .with polyethylene glycolchlorh'ydrins (as shown in the examples) and-withpolyethvlene glycoldichlorides. In every case, lower molecular weight "polyglycoldichlbrids are obtained as the main products' The. extent of degradation(ether. splitting) can be.varied somewhat by the amounts of chlorine andethylene supplied to thereaction, and 'it varies. directly with theseamounts. In mostcases it ispreferable to carry theniethodtohigh overallyields because of the diillculty of recovering the, starting materials.Chlorine and propylene. are onlyslightly less reactive than chlorineandethylene with respect to the polyethylene glycol derivatives, buttheir actiononpolypropylene glycols is not at all energetic. Halogensotherv than chlorine may, of

- course, be used observing'the usual precautions necessarytotheir'sub'stitution for chlorine, al-

though exact equivalence of action may not follow in every case,particularly in the cases of fluorine and iodine.

Various modifications of the method will be apparent and suchmodifications are included within the scope of the invention as definedby the appended claims. 1

This application contains subject matter in common with copendingapplication Serial No. 308,820, filed December 12, 1939.

We claim:

1. Method of making halogenated ethers by splittingcarbon-to-oxygen-to-carbon linkages in open chainaliphatic compoundscontaining more than two such linkages to form halogenated etherscontaining fewer ether linkages than the number of carbon-to-oxygento-carbon linkages in said aliphatic compounds, which comprises causinghalogen and an unsaturated hydrocarbon to react with said aliphaticcompounds and separating said halogenated ethers from the products ofreaction.

2. Method of making chlorinated ethers by splittingcarbon-to-oxygen-to-carbon linkages in open chain aliphatic compoundscontaining more than two such linkages to form chlorinated etherscontaining fewer ether linkages than the number ofcarbon-to-oxygen-to-carbon linkages in said aliphatic compounds, whichcomprises causing chlorine and an unsaturated hydrocarbon to react withsaid aliphatic compounds and separating said chlorinated ethers from theproducts of reaction.

3. Method of making chlorinated ethers by splittingcarbon-to-oxygen-to-carbon linkages in open chain aliphatic compoundscontaining mor than two such linkages to form chlorinated etherscontaining fewer ether linkages than the number ofcarbon-to-oxygen-to-carbon linkages in said aliphatic compounds. whichcomprises causing chlorine and an olefine to react with said allphaticcompounds and separating said chlorinated ethers from the products ofreaction.

4. Method of making halogenated ethers by splittingcarbcn-to-oxygen-to-carbon linkages in open chain aliphatic polyethersto form halogenated ethers containing fewer ether linkages than thenumber of carbon-to-oxygen-to-carbon linkages in said polyethers, whichcomprises causing halogen and an unsaturated hydrocarbon to react withan open chain aliphatic polyether containing at least three groups ofthe class consisting of alkvlene groups, CnHzn, and substituted alkylenegroups wherein the value of nin any of such groups does not exceed 8 andin which each of two vicinal carbon atoms of at least two of such groupsis connected with an oxygen atom, and thereafter separating saidhalogenated ethers from the products of reaction.

5. Method of making chlorinated ethers by splittingcarbon-to-oxygen-tc-carbon linkages in open chain aliphatic polyethersto form chlorinated ethers containing fewer ether linkages than thenumber of carbon-to-oxygen-to-carbon linkages in said polyethers, whichcomprises causing chlorine and an olefine to react with an open chainaliphatic polyether containing at least three groups of the classconsisting of alkylene groups, CnHzn, and substituted alkylene groupswherein the value of n in any of such groups does not exceed 8 and inwhich each of two vicinal carbon atoms of at least two of such groups isconnected with an oxygen atom, and thereafter separating saidchlorinated ethers from the products of reaction.

6. Method of making chlorinated polyethylene ethers by splittingcarbon-to-oxygen-to-carbon linkages in open chain polyethylene etherscontaining more than two such linkages to form chlorinated polyethyleneethers having fewer ether linkages than the number ofcarbon-tooxygen-to-carbon linkages in said polyethylene ethers, whichcomprises introducing gaseous chlorine and gaseous ethylene into a bodyof liquid polyethylene ethers ofthe class consisting of polyethyleneglycol chlorhydrins and polyethylene glycols of high average molecularweight, the ethylene being in excess of the chlorine on a molarequivalent basis. and thereafter separating chlorinated polyethyleneethers of lower average molecular weight from the prod-' ucts ofreaction. I

7. Method of making chlorinated polyethylene ethers by splittincarbon-to-oxygen-to-carbon linkages in open chain polyethylene etherscontaining more than three such linkages to form chlorinatedpolyethylene ethers containing no more than three ether linkages, whichcomprises passing gaseous chlorine and gaseous ethylene into a mixturecontaining chiefly polyethylene glycol chlorhydrins of molecular weightabove pentaethylene glycol chlorhydrins, the ethylene being in excess ofthe chlorine on a molar equivalent basis, and thereafter separating di-,triand tetraethylene glycol dichlorides from the reaction mixture.

WALTER J. TOUSSAINT. LOUIS G. MACDQWELL, JR.

CERTIFICATE OF CORRECTION. Patent No. 2,352,715. July 1;, 19th.

WALTER J. TOUSSAIN'I, ET AL.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows; Page 2,second column, line 8, for "650 -0." read "65 C.--; and that the saidLetters Patent should be read with this correction therein that the sememay conform to the record of the case in the PatenlteeifliaeErazerSigned and sealed this 29th day of August, 'A. D. 191414..

(Seal) Acting Commissioner of Patents.

